# RUN: llc -run-pass simple-register-coalescing -O0 -mtriple x86_64-pc-linux-gnu -o - %s | FileCheck %s

---
name:            foo
tracksRegLiveness: true
body:             |
  bb.0:
    undef %18.sub_8bit_hi:gr16_abcd = COPY undef $al
    %1:gr16_abcd = COPY killed %18
    dead %8:gr8 = COPY undef %1.sub_8bit_hi
    $al = COPY undef %8
...

# This used to hit an assertion:
#   lib/CodeGen/RegisterCoalescer.cpp:1110: RegisterCoalescer::reMaterializeTrivialDef(...): Assertion `ValNo && "CopyMI input register not live"' failed.
#
# CHECK_LABEL: name:            foo
# CHECK:       bb.0:
# CHECK-NEXT:    $al = COPY undef %2:gr8
